I wouldn't be all that surprised to see Suzanne turn up eventually in a video, considering how many
other family members Al has already managed to find parts for, but touring is
hard work. And Suzanne may have, like, an actual
job, for which cheerleading might not be part of the optimum career path. And the main perk of being a Smells Like Nirvana cheerleader is the chance to meet Al & the band. She's got that part taken care of already.
Speaking of Al finding roles for family members, I looked up Nick and Mary Yankovic once on the Internet Movie Database. And every role they had listed was as father and mother of Weird Al Yankovic. Shouldn't they be starting to get a little concerned about typecasting? Branch out a little for the sake of their careers?